Something else to take into account. The first loads in .357 mag. (1935) went in the 1525 FPS range with an 8.75 inch barrel. (Later shortened to 8 3/8 to comform to NRA target match regulations.) That was with a 158 Gr. bullet. What is it now? 1250 to 1300 FPW with 158 gr. bullet? The .44 magnum, 1550 FPS in 1956 with 240 gr. bullet. What is it now? around 1250 to 1300 FPS. The .357 used to be a pretty fair deer round, but with the advent of the S&W model 19 and 66, the original loads shook them up pretty quickly with endshake and other problems. (They kicked like hell too, take it from me.) The S&W 29 and 629 are based on a design that came out in 1905, that really did not hold up taht well. (My 629 lierallt destrroys it's hammer/trigger relationship in 200 to 250 rounds of the current ammo.) So the factories downloaded both rounds. .357's loaded to original specs in S&W 27's and 28's are potent rounds more than suitable for deer, and hogs as well.
BTW. The comment about Alliant seemingly making a change in #2400 is well founded, based on my experience with that powder in .357 and .44 Magnums. I think that since DuPont sold out to IMR, the same thing may have happened there as well, although this is based on one lot of powder in one cartridge.